Starting with electrics and at the same time burning a couple of motors...
Nov 07, 2006
 

I knew that I would need and electric motor for my boat. But what motor and what boat? Looking at the Tower Hobbies catalog I saw that the Bud Light was almost ready to run, the motor was included with the kit, and that I should power it with 12 cells. It was my choice because I always had a preference for cats. I assembled the boat and I went to the lake to test it and have some fun.

It was not bad, with runs around 3 minutes and good speed. But I wanted more from the boat and a motor replacement was a priority. The motor seemed so unsophisticated and from the WEB I knew that there were some really hot motors around. The MS4 had bushings and the ball bearing motors were no so expensive. I chose a Trinity Speed Gems Quartz (19 turn) and after the first MS4 meltdown. After the first run with it, 12 cells was too much strain for the motor and it also melted. I started to think that the speed controller was a piece of junk and the responsible for my troubles. And in fact it was...but not the only responsible for the meltdowns.

I bought a Tekin 432M and, still with 12 cells, I found that the voltage was too much for the motor. These 540 are for a maximum of 7 cells. The endbell melted at the top and the bearing shifted out of position causing the armature to stay misaligned. Cooling the motor was a top priority and the whole setup was installed - brush and can cooling. After some careful readings I found that cooling was common practice with this kind of setups.

This was the final setup on the Bud Light. I wanted to get sure that the heat would not cause more trouble.

There is however a big difference between American and European fast electric racing rules. The duration of the races in Europe is bigger than in America. Some classes have a minimum of 5 minutes. And they need to go fast also.

I didn't understand the relation between winds, rotation and propeller size. Everything was wrong - The winds were to low (by this time I had a really hot 12 turn installed) and the run times went down to 1 minute with less speed than before. The cooling was preventing the motor to cook, but at the end of the run the packs were so hot that I couldn't hold them. Something was definitely wrong. Gearing the motor could be a way to go if I had a way to put a gearbox on this outboard unit. A hot motor geared at around 2:1 and a big (X440) prop could do the trick.

The secret behind a geared motor is to keep the motor on the best rpm (allowing the motor to be more efficient) increasing the torque to allow bigger props that are also more efficient. These beauties cost around $50.00 and the best you can get are made by Hughey Boats. In Europe we can find the Colt gearboxes (around £25.00 at Prestwich Model Centre). The advantage with the Hughey is the number of optional gears that are available. The Colt has a fixed gearing.

The cost of a good electric and all the mods needed to have a competitive and fun boat are very high, and nitro boats started to seem a much better option and the electric boat was used as a retriever...(a very expensive retriever)

The second electric - The TARGA
and the basic principles of electric motors

Even after all this trouble with the Bud, electric boats still had some appeal and Prestwich Model Centre sells one called Targa. I ordered one expecting to have a better understanding of electric boats and motors.
Until the day of the first run, I was very skeptical about the success of my efforts. But after all, there were guys running electrics with excellent speed and good tun times in other parts of the world. This was not black magic, there must be some logic about these motors.

1. Allow your motor to turn
If you load the motor too much (with a big propeller) the amp draw will go up and your duration will come down. Chances are that you burn motors one after the other.

2. Less turns, more amp draw and higher rpm
I was choosing motors with less turns than ideal. The run times were getting really low. The more turns, lower the amp draw and lower rpm's. So, to get the same amp draw you can increase voltage (V=R*I) and that's why you can go with more cells on higher wind motors. The MRP MS4 is a 22 or 23 turn motor as I found when it burned, and I unwind it just to check...

3. Small propellers at high revs are not efficient
They'll cause lots of cavitation (with a characteristic noise) and the boat runs slower. Have a look at the surprising results I got with the X438 and the D3.

4. If the motor and battery are too hot
This means that you are probably using a propeller too big for the setup. If the motor is too loaded then the amp draw goes up and duration will come down (see 1.). The solution is to use a smaller prop, or a milder motor.

With these basic principles in mind, I decided to go for the Trinity D3 17 turn triple. It seemed that the balance between amp draw and rpm would give a good running time and speed.
Cooling was installed from the start and with an Octura X440 (really surface) I went to the lake.
Good! The run times were OK and the speed was more than OK. The tests showed that I could get above 3 minutes at full speed.

The factory timing of the motor would allow 2:30 minutes of running time with amazing speed and acceleration, but I reduced the motor advance to 10º and was touching the 4 minute barrier. This was a very important goal because this boat class has 5 minute races, and even though I was not racing, it is a good practice to compare yourself with some standard. I was sure faster with 30º, but in a race I would barely reach half of the race.

Like all good things in life the D3 motor reached the end. One day the brushes were too short and the motor springs couldn't make them touch the commutator with enough pressure, the sparking and temperature on the brushes got so high that half of the endbell melted, forcing me to change the motor.

The previous table shows some data that can be against all rules. A bigger prop resulted in longer run times!!!. It can be a problem with the measurement or there is some factor that I don't know. I checked and rechecked but there was no explanation for this. The X438 prop also resulted in lower speed (this is consistent with what I know).

I only had one D3, so I installed the SpeedGems Quartz 19 turn for the rest of the day and surprise!

The speed was higher than with the D3 with 10º and the duration was always above the best with the D3 - 3:45. On the first run I got 4 minutes. I had a current draw higher than the D3 (2.3A vs 2.07A) but I had more rpm and a cooler motor and pack at the end of the 4 minutes.

Use hard brushes and very hard brush springs. Sparking due to soft springs results in less power and torque. The temperature gets higher, the commutator burned and the only one that gains is the shop that sells you the motors :-)

The site where I found the most useful information about the basics of fast electrics was the International Waters site, in particular an article by Jay Turner (below). I published this article here because, as you know, IW is closed. I hope that it may help solve some problems you may have.
As I said a good book always helps a lot. I got one from Airage Publications called "Fast Electric R/C boats" by Jay Turner and it is full of good advice. The American scene is very different from the European scene, but some things are the same. Motors, batteries, ESC.

Cars and motors (or how simple things can really puzzle you...)

Let's assume you know everything about motors for electric boats. You may think, like I did, that it applies with very little adjustment to cars. Nope, it doesn't. The current involved is usually lower and the stress on the brushes and commutator is also smaller.

My approach was - buy as many motors as possible, for choosing the best results from testing.
So I did. I bought a couple of Orion Orbital Pro BB, a couple of D4's and I already had a good choice of ESP and Speed Gems.

After that I liked the looks of the Orion Chrome Touring so much that I bought a 11x3 at Apex Models. 

These opinions are not based on dyno testing, but with actual running with race conditions on a particular car model - HPI RS4 Pro 2. Sometimes the dyno testes say one thing and you can never get it with your motor, isn't it?

You can see that with some motors they are fine when brand new, but degrade very fast. After that (even with comm truing and new brushes) they never go to the same level again. If you are a sponsored driver, with free motors, then you probably don't care. However if you spend $50 for each little beast that you buy that's another matter. It hurts!!!

Dynamometer

I can hear a lot of people saying things like:

"Dynos are useless because a good motor on the dyno is not a good motor on a car"

"they don't test the motors as we need for running and the results are meaningless..."

and other statements similar to these.

All these things are not ruled by inexplicable happenings, but rather by scientific and measurable behaviors. There is no way to know if your motor is more powerful than another motor by hearing the sound pitch. It may tell you something, but by no means all the you want to know.

Since I have the CS Dynamometer I can see that my knowledge on motors has gone sky high. Once the rules are understood, choosing the right ratio has become very simple.

By looking at the values of a dyno run you can see what kind of ratio you should be using. There is no such thing as a motor good on the dyno and bad on the track. Chances are that the results are not interpreted correctly.

What seemed like the first exception proved to be the most important confirmation of this principle. My Reedy TI 10x2 gave some poor values when new, but on the track was a very powerful and capable motor.
When I returned home the motor was tested again and it was in fact one of the best motors that I have. So the track experience was confirmed with the results after the brushes were seated correctly and the BB's had been run in.

I'm not saying that you should go out in a rush and spend $400-$500 on a dyno just because it makes you a better driver. However, if you have a friend that owns one, let him test your motors so that you can understand better the way the values match your "feeling" of the motor.

Hand wound Motors

Trinity D4

The first time I installed the D4 9x2 I was amazed. The car was too fast for my skills. With a conservative gearing of 35/122 I could do 5:30 with a 2000 pack and had a lot of speed.

However the motor was very hot at the end of the run. I was expecting a much cooler motor due to my experience with boats. In spite of all the speed there were guys going by me in the straight. What could I do? Use a bigger pinion of course. Faster but hotter. Way too much for my taste. At this time the comm was showing some wear and I decided to skim it a little. I did that and installed a pair of racing brushes.
The next day the car was running perfectly...for 2 runs. The brushes were gone and there was black dust everywhere. The comm was badly burned, and needed another skimming after just two runs. Very disappointing.
The very nice copper hoods and tabs just break turning your motor in a very good candidate for spare Trinity parts. Not a very good durability for a $50 motor.
According to one of the top drivers that I know (David Spashett) this motor "likes" 4380 brushes from Trinity, and with a combination of hard springs and these brushes they can make the motor deliver a lot of rpm and a very good durability.

Dyno testing results can be seen here

Rating:

Orion Chrome Touring

I decided to use the Orion Chrome Touring 11x3. With the same gearing, the car was slow but after some time (6-7 runs) the brushes were ok and the comm seemed brand new. I also noticed that the motor was barely hot at the end and I just attributed this to the gearing I was using. I decided to be bold. For top speed (and after reading the suggested gearing at Team Orion page) I installed a 36 pinion with a RR 155 spur.
Brute speed! Huge acceleration and 5 minutes run time. What more could I ask for? Nobody believed that I had a 11x3 on the car. NOBODY!
And the amazing thing was the fact the the motor is COLD after the run. I mean, really cold.
It was with this motor that one of our best drivers tested my car. He went to the store and bought one for him. Not a motor, but a car. I never told him about the motor .

Dyno testing results can be seen here

Rating:

Integy 7.5 10x3

Wandering around the Internet has some advantages, and I found an identical twin of the D4 for less money. The Integy 7.5. It's absolutely identical in every respect except the brushes and a somewhat dirty armature (quality control ??).
I bought a 10x3 and started my personal testing. Heat build up is the same. These motors get so hot that is almost impossible to find a better gearing just by touching them. Can you tell the difference between 80º and 85º just by touching a motor? I don't. After 4 runs the brushes were gone and the dust typical of high silver content was there. Everywhere. I trued the commutator and I had to cut a lot after just 4 runs. After assembling the motor and installing new brushes I tried to run them in a little bit. The motor was stalled. After inspection I noticed that the armature was touching the magnets. I removed them and I was surprised to see how easy it was to remove the plastic clip. A grain of sand was behind one of the magnets causing this rubbing. Removable magnets!! What for? I'm getting really sick of these so called technological advances.
Run time with a 2000 pack is just 4:45 with 35/115 gearing. And it even got below 5:00 with a 3000 matched pack!!!.

Dyno testing results can be seen here

Rating: (based on the dyno results I have to change the rating to ). And now that I know that the gearing needs a tweak, it'll probably go up a thumb...

Fantom Modified 10x3

This baby rocks! What an amazing motor. After preparing it (capacitors, lubrication of BB etc) I plugged the motor to my Whatt Meter just to check consumption. The first thing I noticed was a very high pitched noise. It was doing much more rpms than the D4. This was the first impression. The next day,  I just installed it with a 120/32 combination and I was doing laps at least 1 second faster than the same setup with the D4 9x2. I made several runs of more than 5 minutes with a 2000 pack. After 9 or 10 packs I went home after I noticed that the brushes needed replacement. 
I took .15 mm of the commutator. Amazing, after 9 or 10 packs. I installed a new pair of brushes (this time a little harder than the original pair) and the high rpm noise came back. It's alive!
A beast with torque and rpm. It goes to my shopping list. Trinity is falling back...

Dyno testing results can be seen here

Rating:

Corally Pro Series 10x2 and 9x2

I've run this little devil (6 Oct 2000) and it rocks. With a 120/37 ratio outperforms several 9x2 at the track. Amazing top speed. On the tight corners it's also a pretty strong contender. It just very good overall. After 12 packs, barely needs skimming of the comm and the brushes (original) just lost 1mm when compared with a new one. Corally includes another pair of brushes on the package. No SMT capacitors, but conventional ones and already installed. VEEERY good value for money (if you live in Europe it's even better).

PS -  My D4 armature was gone and I saw a very good price on Corally handwound armatures. Like a lot of modelers I can't resist a good bargain and I ordered one. I installed the brand new 10x3 arm on the old D4 can...and what happened?. The Corallinity or Trinitally is faster than the original D4 and the motor is cooler at the end of the run. My decision is final - I'll only buy Orion or Corally motors from now on.

The 9x2 was a disappointment. The motor feels like it has no punch and after comm truing and tuning it shows values normal for a 10T motor, except the rpm that reaches 52.000 rpm. However it doesn't seem to deliver the power on the track, when compared with the Fantom or the new Reedy Fury MW.

Dyno testing results can be seen here

Rating:

Peak Aurora 10x3

Remember the bad experience with the Epic can motor (D4)? And do you remember the wonderful experience with the TOP motor (Orion) ?
This is a TOP  based motor with all the gimmicks you can get. Installed capacitors, epoxy balancing etc etc.
I had this motor sitting in the box to use sometime, but the low RPM kept me away from it because I had more powerful and higher revving motors. Anyway I decided to give it a go. And it sure paid off. After 2 runs and another skim the values of power output, torque and rpm have gone up. it's now in the 49000 range and somewhere around 210 Watts. It's now one of my first choice motors.

Dyno testing results can be seen here

Rating: NA

Reedy Fury MW 9x3

This motor is until now the most powerful motor that I have. It has very good numbers on the dyno and it shows on the track. The motor is very fast when compared to the Corally 9x2. It remains cold after a 5+ minute run with 21/78 on the Yokomo MR4 WCR. I believe that it's the perfect choice with 3000 batteries. Good acceleration and very good durability for such a hot motor.

Dyno testing results can be seen here

Rating:

Reedy Ti 10x2

Strange motor. The numbers say it's not powerful (compared with the 10x3 I have), not to much torque and the rpm is so so. BUT, on the track it rocks. I had to gear up from the original 21/78 (MR4TC) ratio and every time the pinion went up a tooth, the motor was colder at the end and the car was faster. I can do 6:30 minutes at race rhythm. I ended with a 23/78 for a long track and 22/78 for the short track (electric version). Good acceleration and good top speed with the 23 pinion.

Temperature at the end of 6:30 minutes - 45ºC batteries temperature 59ºC. Amazing isn't it?

After 6 packs the comm is barely scratched and only a minor touch was enough. I guess I can attribute this to the new LRP Quantum Competition. I can see my motors in very good shape at the end of a racing day or practice session. The Novak seems to be harder on the comms. Don't ask me why, I don't know...

Somehow this motor gets better with the use. The values jumped to some of the best I ever got after one commutator rectification. This explains why the motor was so good at the track.

Lesson to be taken - Run your brushes before going to the track. The benefits are enormous.

Dyno testing results can be seen here

Rating:

Machine Wound Motors - Stock (27 turns, fixed timming)

Trinity P2K Pro

I'm using this motor on my 1/12 car. I used to run a Trinity Speed Gems Quartz (19) and I was very difficult to beat. One day I saw this motor at my LHS for a decent price and I bought one. Using the same ratio (18/75) the car could lap on the same time as with the 19t. Less top speed, but very good low end power was perfect for an intricate track like the one we race on. One day I decided to put comm drops on the motor...and the oily paste made of carpet threads and oil caught fire and the comm was badly burned. However a visit to the lathe gave the motor new life. I guess that this can be one of the motors to beat on this class and on our track. A proof of that was the thundering victory on the first outing (7 lap difference). I guess that I can give a 3 thumbs up due to the ratio price/performance of this motor. If you need to know EVERYTHING about this motor and tricks to tune any motor, Ask Big Jim Greenemeyer on this forum - http://forums.about.com/ab-rcvehicles/messages/

Dyno testing results can be seen here

Rating:

Reedy Rage Type R Stock

I never know if I have the best motor of the class. Do you? This was why I decided to test another stock rebuildable motor. Using the same ratio (18/75) again I won a race with my 1/12. The motor feels a little different from the P2K, and the pack duration is a little higher. It seems it lacks the same ballistic power out of the corners. The dyno showed me why. The price is more or less the same and the performance will closely match the P2K. A good brush break in is needed in order to eliminate the sparking and to allow the brushes to seat well on the comm. It'll take about 5 minutes at 5 volts to do it. I'll be absolutely sure about this when my new CS Electronics Dyno arrives (oh yes! I'll have a new toy...). But for now the choice of motors for my 1/12 is between the Reedy and The P2K. Very good price, good performance and no copper hoods to break....

Dyno testing results can be seen here

Rating:

Machine Wound Motors

Orion Orbital Pro 2 BB 12x3

My first modified motor. I can't even remember where I bought it. My RS4 Rally was incredibly fast with it. So fast that I destroyed the body in one or two sessions playing alone. I still think that these motors are a very reasonable alternative to the maintenance hungry hot hand wounds. It has ball bearings, purple brush hoods (as we all know this is a very important factor in performance...) and installed bullet connectors and caps. The price is right and the performance is not bad either. A hotter wind could cause some embarrassment to the "2x1" motor guys around here...

Dyno testing results can be seen here

Rating:  

Wrap up

As you can see I just don't like the D4 and derivative by Integy. It's just about performance when they are new. After the first comm retouching they are never the same again. Maybe I'm not using the correct brushes, but I'm using the ones that Trinity suggests. This way I wont try Trinity motors again.

The Fantom revealed itself as an incredible power house. I was running with a guy that owns a TC3 with a Peak 9x3. He was very impressed with the motor. I could catch him easily. If only my driving skills were better...

The Corally is awesome! Almost cold after 6 minutes with plenty of speed and low end power (you should see the car go by a TC3 with a D4, eh eh). Very durable comm and the arm is a piece of art. Big Jim Greenemeyer (designer of the P2K and D4) says that the winds that are aesthetically pleasing are not the ones that perform better, but they sure look good. According to "Big" Jim, there were some considerations regarding the marketing of the D4 that caused the motor to be less good than it could be. However the pros win lots of races with it. I also know what is to be forced to deliver an inferior product due to marketing considerations. And it hurts...

The stock motors that you see in the test are the ones I'm using on my 1/12 RC12L3. They allowed me to win the races I entered. The car is tuned to perfection and the motors deliver whatever I ask. Speed, torque and they are able to run for 18 minutes with a 2400 (unmatched) pack. I'll install one of these in my RS4 Pro2 just to see what a stock motor can do on a 1/10 4WD, as soon as the weather allows.

Motor	Performance	Construction /Packaging	Durability	Price	Rating (-3 to 3)
Trinity D4 9x2		(SMT caps)
Orion Chrome Touring 11x3		(SMT caps)
Integy 7.5 10x3		(SMT caps)
Fantom 10x3 (Yokomo can)
Corally Pro Series 10x2		(Includes extra brushes, caps installed)
Peak Aurora 10x3		(SMT caps)
Reedy Fury MW 9x3		(capacitors installed)
Reedy TI 10x2		(capacitors installed)	NA
Trinity P2K Pro		(SMT caps)
Integy 7.5 10x3		(SMT caps)
Trinity P2K Pro		(SMT caps)
Reedy Rage Type R Stock		(Includes extra brushes)

Some thoughts...

Recently I was at an European Championship event and I could see that some of the drivers (and pit men) have an approach about motors that is difficult to understand. Everybody thinks that the motors that the pros use are far better than theirs. The fact is that they don't touch the motor timing, have no idea of Amp draw, and think that loosen the endbell and getting a little more RPM by advancing the timing without getting too much Amp draw is some sort of a mystery. Nobody (I mean, NOBODY) reads a book about electrics or even tries to understand what an electric motor is. Some of them (of course there are knowledgeable people around here) just hope to have a good motor by divine intervention.
When you talk to a pro this is tacit knowledge. They have it by experience and also by reading and understanding the way these things work. It may help or it may not. The truth is that if you don't know then it doesn't help you. For sure!!

Like this it's very difficult to attain the nirvana of electric cars. It's no surprise that our best drivers run nitro cars. An electric motor has so many adjustments that can result in differences of thousands of RPM, that a small mistake can ruin your chances from the start. Brute force is not the way to go.  Finesse and knowledge are better.

Motor timing - The unknown factor

I've noticed that many drivers have a very superficial understanding of one of the main factors of motor tuning. The timing, when properly adjusted may be the difference between ending in first or finishing miserably after a premature pack dump.

When we buy a new motor, the manufacturer adjusted it for a set of conditions that is the estimated average. That doesn't mean that it is correct for our track, car and batteries that we use. It must be adjusted like all the other parameters on your car.

Having an idea of current consumption when free running is a top priority. If your motor does 10 amps at 7.0V free running, then you have a problem. When loaded that motor will draw a pack in no time. You must adjust the timing in order to have up to 5 amps of current draw (the results from the dyno tests are done with a flywheel installed and the Speed Gems draws only 2.4A). Put it on the car and do a test with your pack and normal gearing. The Gear Calculator will help you to know what spur and pinion you need to have the same killer combination of the winner. The runtime is enough? Just enough? Are you some laps behind the winner on this track? If you are you probably need a motor with more rpm in order to compensate the lack of speed.
If, on the other hand, you left lots of time on the pack, try to use a bigger pinion (one tooth on the pinion has much more effect on the final relation than one on the spur) in order to have more top speed. When you reach a safety margin of a race duration and at least one lap more you have reached the correct setting of advance for that gearing, car, battery and track. If even with that effort you are still slower then the other guys might be using motors with a different winding or bigger packs.

Motor advance must match the current that the motors draws. There is a way to know if you are using the correct amount. You just look at the commutator plates. If you have too much advance the plates are burned at the leading edge.
If it is insufficient they are burned on the trailing edge.
How do you know which is which?
Pick up your armature with the comm facing up. The leading edge is on the left side of each comm plate and the trailing edge is on the right side.

If you ever trued a commutator you probably saw this already. One side of the plate is in worse shape than the other. Timing error.

This happens because current doesn't flow instantaneously from the brushes to the comm. The time it takes to do that is what we are trying to adjust when adjusting motor timing. Because we only adjust the timing in advance that usually the way we refer to it - advance. We never retard the timing. The motor will draw more current and it will overheat causing it's destruction. Never do it wrong. When you assemble a motor the wrong way, on top of being rather humiliating to do a wonderful start backwards, what happens is that the motor has some amount of timing retard. The same amount it used to have of advance.

Other things that have influence on motor behavior

Brush alignment
Sometimes the brushes (brush hoods) are misaligned. There are tools for aligning the brush hoods. They are compatible with normal or laydown brushes. One of them is made by Parma and it's called Brush hood alignment tool. After unscrewing the brush hoods put this tool in place and screw the brush hoods again. It's done. Beware! The copper hoods that you can find in the Epic cans are the most temperamental that I've ever seen. They have a life of their own, and they do show it by moving out of alignment with incredible ease. 

Springs
The experts use a harder spring on the positive brush. Andrew Moore's father explained me the concept. You reduce the overall pressure on the comm (allowing it to rotate faster) but avoid the sparking that can cause premature wear of the comm and ultimately it's destruction.

Brushes
And I thought that all the pros used silver brushes!! Dave Spashett and Andrew Moore use copper brushes on their D4. If you want to save some money in new brushes, you can buy a slotter/serrator. There are a couple of them on the market, but one of the more versatile is made by Trinity and it's called Brush Factory. It allows you to serrate or slot brushes.  Instead of putting a new pair of brushes, if they still have a good size and are not blue at the tip, just use this device and you brushes are serrated or slotted like when they were new. It costs around $70. How many pair of brushes does that pay?

Motor Shims
Motors come with metal shims to avoid armature slop. There are Teflon shims for this effect. They reduce drag and consequently give you more rpm and less consumption. Use them if possible. It's not everyday that I get a guestbook entry by the creator of the P2K and the D4, "Big" Jim Greenemeyer. You should only use Teflon shims with stock motors. On bb motors use metal shims.

Comm truing
Even with a new motor this can be considered. Sometimes the comm it's not cylindrical on a brand new motor. Check it and you'll be surprised. I was.

The lathe
I have one Team Cobra and the Cobra Varidrive that allows me to use a 12V power source and adjust the motor rpm. Even if your lathe is made by someone else, this Cobra Varidrive is really worth it (to read about it go to http://rcvehicles.about.com/hobbies/rcvehicles/library/reviews/blrev_varidrivea.htm). It's a real pain to charge and recharge a pack for truing some motors. Trinity, Orion and Integy have excellent lathes with carbide tips around $80. A good oil is also a must. I use Team Cobra oil and the results are excellent. Very different from not using any oil at all.

What can you do to improve speed and run time...

Go brushless!!!

I had a brushless motor for my boats. What you can have with these costly (just on the beginning) pieces is a very powerful and efficient system.

These thing can be severely under geared or severely over geared and achieve run times that are beyond our experiences. I mean 10 minutes and more, making a 9 or an 8 look like a kid's toy.

However, the majority of these motors was designed for planes or boats, and the power band was not very adequate to cars. Especially the ESC's that could overheat and shut off in the middle of a run.

Knowing this, a UK company (ModelTech) created a series of motors and a speed controller to suit the RC Car needs. Here it is! This little beast delivers the same rpm of a 9 or good 10 and it has no wearing parts (cool, isn't it?). I mean no brushes or comm at all.

The only thing that can have some wear is the shaft and the two bearings that support it.

The power curve is a bit different from what we are used to. It's not a steep curve, but instead a more flat curve. This means that the power at a lower rpm is several Watts higher than a normal motor. The efficiency is much higher than in normal motors. Remember? No drag caused by rubbing brushes against the comm?

I'm going to put this motor on my Pro 2 and test it. But I'll wait a practice day for a race. I want to see those faces when I go by their cars like a rocket and still run for 10 minutes. It's going to be fun. 

The combo (ESC and motor) comes in this neat case and an adaptor for the normal mounting positions in aluminum is also included. The ESC is packed with features, but I guess that you'll be better informed if you read the Modeltech site.

These motors are not for the faint hearted because they can cause wheel spinning when you accelerate on the straights. Talk about adrenaline!

This is a sensorless motor and the ESC was designed for this type of motors, but it can be used with sensor motors like the Aveox (just don't connect the sensor wires). In fact, Modeltech claims that those motors can see their performance improved if you use a sensorless controller with them.

These things are serious engineering pieces and they are not allowed to race in sanctioned races around the world. I guess that's because the market of "normal" motors would suffer a breakdown if everybody started to race with a motor that doesn't need maintenance. Imagine all the brushes you don't have to buy, and springs, no lathe, no comm drops, no replacement armatures, etc etc.

If the cost seems high in the beginning, try buying 2 mod motors, an ESC, a lathe with diamond bit and a couple of spare brushes and springs. If you add it all you will see that the cost is covered already. If you are a hardcore racer and race for an entire season, add a few motors and spares more, without forgetting the cost of the services of a spin doctor (it may help. We never know).

Are you convinced? I guess that Novak is, because it is releasing their own motor ESC combo this summer.

They must know something about how to disrupt the very profitable market of Mr. Earn Profitti (big T) and big O and big R. If the big ones don't follow they end up selling motors at 5 bucks a dozen, because the backyard racer will buy a motor that needs no maintenance.

If you put one of these motors against the best modified made especially for one of the sponsored guys, the driver will have a stroke. Of course that the skills count, but if you don't crash you'll make them look like rookies...

Read the test here

Motor limits - Much ado about nothing

The motor limits. Before this year championship we had to decide to follow (or not) the 12 turn motor limit accepted by all the European countries.
As usual, we have a tendency to do things our own way, even if they have costs that we'll pay further down the road.

So, we decided not to follow this limitation and be an oasis in Europe where you can run with the hottest modified you can get. Why? Because we need to "protect" the investment of the racers that bought several motors below this limit.

I'm always amazed by the way decisions are made, by voting or otherwise and this may have perverse effects on race attendance.

There is a certain feeling of frustration with the so called "sponsored drivers". These drivers can obtain spares for a highly discounted price (and some of them, I believe, for free) allowing them to have an abundance that cannot be matched by the other drivers, unless they spend huge amounts of money during the season.

We can see boxes of tires, motors batteries and those things that can make you cry. The idea that the more money you throw away, the faster you go, is settled in the racer community for a long time. And it's here to stay.

What really amazes me is the logic behind this. Our market is small, very small, and I can't understand how the dealers can just give these quantities of tires, batteries and motors without something in return. For some shops, giving $2000 worth of goods may be equal to give the profit of an entire month. I'm sure that it's very difficult to obtain a sales result comparable to the effort of sponsoring one or two drivers.

On top of that, many drivers are buying their stuff outside of the country, helping to drain an already weak market. The Internet and the European Community can be a very effective way to get products that we can't find here, or at a price sometimes considerably lower than the prices on the Portuguese market. If I can get prices and availability of stock outside of Portugal, I'll do it. Why? Because I can call Apex Models or Tower Hobbies and they put the goods in my house in 5 working days. If I try to BUY a Vectra 190mm body around here I'll probably have to move from shop to shop, and in the end they've run out of stock and I'l have to wait a month for that body.

If I call a big UK mail order shop they just send it in 3 days. The same goes for any other item I want. This is making the buyer less faithful to the LHS. They're there just for the small things. Sometimes even the washers and screws are ordered from abroad.

The price of a 9x2 at our local shop is outrageous, and I'll have to choose from a depleted stock. However if you try to buy a motor above 10 or 11 they look at you like if you were from another planet. I saw a guy selling a 8x1 to a complete newbie with 10º of retarded timing. You know what this means - the newcomer will come back with a burnt motor and probably will give up because of the cost.

I'm in favor of a motor limit for two main reasons:

1. It would decrease the huge gap between the guys that have a motor for an entire race day and the guys that can burn 3 or 4 motors

2. It would prepare our drivers to compete with the same weapons our European counterparts have.

When a batch of hot modifieds arrives at the LHS, the best ones have already been taken apart for a group of exclusive drivers. The difference in RPM and power can be really significant if you get the best 10 of a batch of 20 motors.

The same goes for the batteries. I tried to buy Team Matched packs around here, and the best I could get were the Race Spec batteries. In Holland I buy Team Spec for a lower price than those Race packs in Portugal.

The gap between the sponsored (or more experienced) drivers and the rest of the pack is big. And it would be narrowed with the limit on motors. Instead of destroying one motor per race it would last for 2 or 3 races easily, helping more people to race at the National level. Like this, the costs are very high to the vast majority of the Sunday racers.

The other adverse effect on the sponsored racers themselves is when they have to race abroad. They are not used to race with 12turn motors. This shows on the track. The results will not be that good on the first outings.

Like this, nobody is helping the hobby. It's just helping to decrease the number of racers that do a National Championship year after year.